LC composite component

ABSTRACT

Provided is an LC composite component having a multi-layer substrate, a pattern coil, and a chip capacitive element. The multi-layer substrate is configured such that insulating layers are stacked. The pattern coil forms a coiled shape of which the coil axis extends along a stacking direction of the multi-layer substrate, and includes a coil conductor disposed between the insulating layers. The chip capacitive element includes a ceramic body having a relative permittivity higher than that of the insulating layers and counter electrodes. The chip capacitive element is at least partially disposed within the pattern coil.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure relates to an LC composite component configuredsuch that a coil and a chip capacitive element are arranged in amulti-layer substrate having a plurality of insulating layers stacked oneach other.

2. Description of the Related Art

There is an LC composite component that is configured as an LC filter inwhich a coil and a capacitor that are formed by an electrode pattern aredisposed between layers in a multi-layer substrate are connected (see JP5-335866 A).

According to a conventional LC composite component, a magnetic fieldgenerated within a multi-layer substrate becomes stronger as themagnetic field is closer to a coil. Therefore, if an electrode patternsuch as a capacitor is disposed near the coil, a magnetic flux travelsaround the electrode pattern, and thus an inductance of the coil isreduced. Accordingly, in order to set an inductance to a desired valuewithout changing a configuration of the coil too largely, it may bedesirable to place an electrode pattern such as a capacitor away fromthe vicinity of the coil so as to prevent reduction of the inductance.In addition, it may be desirable to increase an area of the multi-layersubstrate in order to place the electrode pattern such as a capacitoraway from the vicinity of the coil. Therefore, it can be difficult toproduce downsized LC composite components.

SUMMARY OF THE INVENTION

Thus, the present disclosure provides an LC composite component withwhich a desired inductance may be easily achieved and that is suitablefor downsizing as compared to the conventional technique.

An LC composite component according to the present disclosure includes:a multi-layer substrate configured such that a plurality of insulatinglayers are stacked on each other; a pattern coil forming a coiled shapeof which the coil axis extends along a stacking direction of themulti-layer substrate, and including a conductor disposed between theinsulating layers; and a chip capacitive element including a dielectricbody having a relative permittivity higher than that of the insulatinglayers and counter electrodes that face against each other with thedielectric body interposed therebetween, at least a part of the chipcapacitive element being disposed within the pattern coil.

According to this configuration, at least a part of the chip capacitiveelement is disposed within the pattern coil, and therefore it ispossible to reduce a space for providing the chip capacitive element andto downsize the LC composite component. Further, as the chip capacitiveelement is configured to include a dielectric body having a higherrelative permittivity than that of the insulating layers of themulti-layer substrate, it is possible to downsize the chip capacitiveelement, and to prevent reduction of an inductance of the pattern coilas an amount of the magnetic flux blocked by the chip capacitive elementdecreases even if the chip capacitive element is disposed within thepattern coil.

It may be preferable that the above LC composite component is configuredsuch that the chip capacitive element is disposed such that each of thecounter electrodes is in parallel with the stacking direction of themulti-layer substrate.

A direction of magnetic flux within the pattern coil substantiallymatches the stacking direction of the multi-layer substrate. Therefore,by arranging the counter electrodes of the chip capacitive element inparallel with the stacking direction of the multi-layer substrate, themagnetic flux passes between the counter electrodes of the chipcapacitive element. This also reduces an amount of the magnetic fluxblocked by the chip capacitive element, and thus it is possible toprevent reduction of an inductance of the pattern coil.

It may be preferable that the above LC composite component is configuredsuch that one principal surface facing the stacking direction of themulti-layer substrate is a mounting surface facing an externalsubstrate, and a center of the chip capacitive element in the stackingdirection of the multi-layer substrate is displaced toward a side of themounting surface from a center of the pattern coil in the stackingdirection of the multi-layer substrate.

The external substrate on which the LC composite component is mounted istypically provided with a ground electrode or a mounting electrode in aregion that face the LC composite component. With this, in a state inwhich the LC composite component is mounted on the external substrate, amagnetic field generated by the pattern coil becomes weaker on a sidecloser to the mounting surface. Therefore, by displacing the center ofthe chip capacitive element in the stacking direction of the multi-layersubstrate to the side of the mounting surface from the center of thepattern coil in the stacking direction of the multi-layer substrate, itis possible to reduce an amount of the magnetic flux blocked by the chipcapacitive element, and to prevent reduction of an inductance of thepattern coil.

It may be preferable that the above LC composite component is configuredsuch that the chip capacitive element includes a mounting electrodefacing the stacking direction of the multi-layer substrate, themulti-layer substrate includes via conductors respectively on top andbottom in the stacking direction of the multi-layer substrate withrespect to the chip capacitive element, the via conductors extendingfrom the mounting electrode along the stacking direction of themulti-layer substrate as a part of wiring connected to the chipcapacitive element, and the mounting electrode is connected between thevia conductors.

According to this configuration, when viewed along the stackingdirection of the multi-layer substrate, the mounting electrode of thechip capacitive element overlap the via conductor connected to the chipcapacitive element. Therefore, it is possible to use the mountingelectrode as a part of the via conductor, and it is possible to reducean area of the electrode provided within the pattern coil when viewedalong the stacking direction of the multi-layer substrate. With this, itis possible to reduce an amount of the magnetic flux blocked by theelectrode, and to prevent reduction of an inductance of the patterncoil.

It may be preferable that the above LC composite component furtherincludes: a second pattern coil where the pattern coil is taken as afirst pattern coil, the second pattern coil being adjacent to the firstpattern coil on a side perpendicular to the stacking direction of themulti-layer substrate, and forming a coiled shape of which the coil axisextends along the stacking direction of the multi-layer substrate, andis configured such that a direction of magnetic flux within the firstpattern coil is identical with a direction of magnetic flux within thesecond pattern coil, and a center of the chip capacitive element in adirection along which the first pattern coil and the second pattern coilare adjacent is displaced toward a side of the second pattern coil froma center of the first pattern coil.

According to this configuration, as the direction of magnetic fluxwithin the first pattern coil is identical with the direction ofmagnetic flux within the second pattern coil, the magnetic field withinthe first pattern coil becomes weaker closer to the second pattern coil.Therefore, by displacing the chip capacitive element to the side of thesecond pattern coil from the center of the first pattern coil, it ispossible to reduce an amount of the magnetic flux blocked by the chipcapacitive element, and to prevent reduction of an inductance of thefirst pattern coil.

It may be preferable that the above LC composite component furtherincludes: a second pattern coil where the pattern coil is taken as afirst pattern coil, the second pattern coil being adjacent to the firstpattern coil on a side perpendicular to the stacking direction of themulti-layer substrate, and forming a coiled shape of which the coil axisextends along the stacking direction of the multi-layer substrate, andis configured such that a direction of magnetic flux within the firstpattern coil is opposite from a direction of magnetic flux within thesecond pattern coil, and a center of the chip capacitive element in adirection along which the first pattern coil and the second pattern coilare adjacent is displaced toward a side opposite from the second patterncoil from a center of the first pattern coil.

According to this configuration, as the direction of magnetic fluxwithin the first pattern coil is opposite from the direction of magneticflux within the second pattern coil, the magnetic field within the firstpattern coil becomes stronger closer to the second pattern coil.Therefore, by displacing the chip capacitive element to the sideopposite from the second pattern coil from the center of the firstpattern coil, it is possible to reduce an amount of the magnetic fluxblocked by the chip capacitive element, and to prevent reduction of aninductance of the first pattern coil.

The LC composite component may be configured such that a filter circuitis configured by connecting the pattern coil and the chip capacitiveelement.

The LC composite component may be configured such that the chipcapacitive element is a chip capacitor.

The LC composite component may be configured such that the chipcapacitive element is a chip varistor.

It may be preferable that the above LC composite component furtherincludes: a first inductor configured by a conductor extending andfacing the first pattern coil between the insulating layers, andconnected to the pattern coil via the chip capacitive element.

According to this configuration, magnetic field coupling occurs betweenthe first inductor and the pattern coil, and it is possible to adjustinductance of the pattern coil by the magnetic field coupling.

It may be preferable that the above LC composite component furtherincludes: a first signal input/output terminal; a second signalinput/output terminal; and a ground connecting electrode, and isconfigured such that the pattern coil is connected between the firstsignal input/output terminal and the second signal input/outputterminal, the chip capacitive element has one end connected to aconnecting point between the pattern coil and the second signalinput/output terminal, and the first inductor is connected between theother end of the chip capacitive element and the ground connectingelectrode.

According to this configuration, an attenuation pole may be provided forfilter characteristics by series resonance between the chip capacitiveelement and the first inductor.

The LC composite component may be configured such that in a region inwhich the first inductor faces the pattern coil, a direction of acurrent flowing through the first inductor is the same as a direction ofa current flowing through the pattern coil. In this case, magnetic fieldcoupling is achieved between the first inductor and the pattern coil inphase by a positive coupling factor.

The LC composite component may be configured such that in a region inwhich the first inductor faces the pattern coil, a direction of acurrent flowing through the first inductor is opposite from a directionof a current flowing through the pattern coil. In this case, magneticfield coupling is achieved between the first inductor and the patterncoil in reversed phase by a negative coupling factor.

It may be preferable that the above LC composite component furtherincludes: a second inductor configured by a conductor extending andfacing the first pattern coil between the insulating layers, andconnected to the first inductor in parallel.

According to this configuration, it is possible to adjust magnetic fieldcoupling between the pattern coil for each of the first inductor and thesecond inductor, and therefore inductance of the pattern coil may bemore accurately adjusted.

The LC composite component may be configured such that in a region inwhich the second inductor faces the pattern coil, a direction of acurrent flowing through the second inductor is the same as a directionof a current flowing through the pattern coil. In this case, magneticfield coupling is achieved between the second inductor and the patterncoil in phase by a positive coupling factor.

The LC composite component may be configured such that in a region inwhich the second inductor faces the pattern coil, a direction of acurrent flowing through the second inductor is opposite from a directionof a current flowing through the pattern coil. In this case, magneticfield coupling is achieved between the second inductor and the patterncoil in reversed phase by a negative coupling factor.

According to the LC composite component of the present disclosure, it ispossible to downsize the LC composite component as a chip capacitiveelement is provided within a pattern coil. Further, as the chipcapacitive element may be downsized by configuring the chip capacitiveelement using a dielectric layer having a higher relative permittivitythan that of an insulating layer, it is possible to prevent reduction ofan inductance of a pattern coil even if the chip capacitive element isdisposed within the pattern coil. Therefore, it is possible to easilyachieve a desired inductance even with a downsized LC compositecomponent.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view illustrating an LC composite componentaccording to a first embodiment of the present disclosure;

FIG. 1B is an exploded perspective view of the LC composite componentaccording to the first embodiment of the present disclosure;

FIG. 2 is an exploded plan view of the LC composite component accordingto the first embodiment of the present disclosure;

FIG. 3 is an equivalent circuit schematic of the LC composite componentaccording to the first embodiment of the present disclosure;

FIGS. 4A, 4B, 4C, 4D, and 4E are side sectional views respectivelyillustrating steps of manufacturing the LC composite component accordingto the first embodiment of the present disclosure;

FIG. 5 is a side sectional view illustrating an LC composite componentaccording to a second embodiment of the present disclosure;

FIG. 6 is an exploded plan view of the LC composite component accordingto the second embodiment of the present disclosure;

FIG. 7 is an equivalent circuit schematic of the LC composite componentaccording to the second embodiment of the present disclosure;

FIG. 8A is a schematic view illustrating an LC composite componentaccording to a third embodiment of the present disclosure;

FIG. 8B is a schematic view illustrating an LC composite componentaccording to a modified example of the third embodiment of the presentdisclosure;

FIG. 9A is a perspective view illustrating an LC composite componentaccording to a fourth embodiment of the present disclosure;

FIG. 9B is an equivalent circuit schematic of the LC composite componentaccording to the fourth embodiment of the present disclosure;

FIG. 10A is a perspective view illustrating a composite substrate havingan LC composite component according to a fifth embodiment of the presentdisclosure;

FIG. 10B is an equivalent circuit schematic of the composite substratehaving the LC composite component according to the fifth embodiment ofthe present disclosure;

FIG. 11A is an equivalent circuit schematic of the LC compositecomponent according to the sixth embodiment of the present disclosure;

FIG. 11B is an exploded perspective view of the LC composite componentaccording to the sixth embodiment of the present disclosure;

FIG. 12 is an exploded plan view of the LC composite component accordingto the sixth embodiment of the present disclosure;

FIG. 13A is an exploded plan view illustrating a different example ofwiring of a connected conductor;

FIG. 13B is an exploded plan view illustrating a different example ofwiring of the connected conductor;

FIG. 13C is an exploded plan view illustrating a different example ofwiring of the connected conductor; and

FIG. 14 is a diagram exemplary illustrating filter characteristics ofthe LC composite component.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, an LC composite component according to a first embodimentwill be described. The LC composite component as used herein isconnected to an external connecting terminal of a device utilizinghigh-frequency signals, and used as a filter for removing a noise.

FIG. 1A is a perspective view illustrating an LC composite component 1according to the first embodiment.

The LC composite component 1 includes a multi-layer substrate 2, apattern coil 3, and a chip capacitive element 4. The multi-layersubstrate 2 is a hexahedron, and configured herein by a thermoplasticresin such as liquid crystal polymers. The chip capacitive element 4here is a chip capacitor. The pattern coil 3 and the chip capacitiveelement 4 are disposed within the multi-layer substrate 2. Themulti-layer substrate may be configured by a different type ofthermoplastic resin or low temperature co-fired ceramics, for example.

FIG. 1B is an exploded perspective view of the LC composite component 1.FIG. 2 is an exploded plan view of the LC composite component 1 viewingrespective layers from their top surfaces.

The multi-layer substrate 2 includes resin sheets 11, 12, 13, 14, and15. The multi-layer substrate 2 is configured such that the resin sheets11-15 are stacked from a top surface to a bottom surface in order.

The resin sheet 11 includes an insulating layer 21. The insulating layer21 is made of a resin, and its outline is rectangular in a planar viewalong a stacking direction.

The resin sheet 12 includes an insulating layer 22, a wiring layer 32,and a via conductor 42. The insulating layer 22 is made of a resin andincludes an opening 22A. An outline of the insulating layer 22 isrectangular in a planar view along the stacking direction. The opening22A is rectangular in a planar view, and penetrates the insulating layer22 from the top surface to the bottom surface. The wiring layer 32 isstacked over the top surface of the insulating layer 22. The viaconductor 42 penetrates the insulating layer 22 from the top surface tothe bottom surface.

The resin sheet 13 includes an insulating layer 23, a wiring layer 33,and a via conductor 43. The insulating layer 23 is made of a resin andincludes an opening 23A. An outline of the insulating layer 23 isrectangular in a planar view along the stacking direction. The opening23A is rectangular in a planar view, and penetrates the insulating layer23 from the top surface to the bottom surface. The wiring layer 33 isstacked over the top surface of the insulating layer 23. The viaconductor 43 penetrates the insulating layer 23 from the top surface tothe bottom surface.

The resin sheet 14 includes an insulating layer 24, a wiring layer 34,and a via conductor 44. The insulating layer 24 is made of a resin, andits outline is rectangular in a planar view along the stackingdirection. The wiring layer 34 is stacked over the bottom surface of theinsulating layer 24. The via conductor 44 penetrates the insulatinglayer 24 from the top surface to the bottom surface.

The resin sheet 15 includes an insulating layer 25, a wiring layer 35,and a via conductor 45. The insulating layer 25 is made of a resin, andits outline is rectangular in a planar view along the stackingdirection. The wiring layer 35 is stacked over the bottom surface of theinsulating layer 25. The via conductor 45 penetrates the insulatinglayer 25 from the top surface to the bottom surface.

The pattern coil 3 includes a coil conductor 32A and a coil conductor33A, and has an inductance. The coil conductor 32A is provided over thewiring layer 32 of the resin sheet 12, and extends so as to surround theopening 22A. The coil conductor 33A is provided over the wiring layer 33of the resin sheet 13, and extends so as to surround the opening 23A.The coil conductor 32A and the coil conductor 33A are connected by thevia conductor 42 so as to form a coiled shape of which the coil axisextends along the stacking direction of the multi-layer substrate 2.

The chip capacitive element 4 has a thickness substantially equal to atotal thickness of the resin sheets 12 and 13, and is contained within acavity defined by the openings 22A and 23A. As the openings 22A and 23Aare provided within the coil conductors 32A and 33A, the chip capacitiveelement 4 is disposed within a coil of the pattern coil 3.

The chip capacitive element 4 includes a ceramic body 5, a plurality ofcounter electrodes 6, and mounting electrodes 7A and 7B, and has acapacitance. The ceramic body 5 is configured such that a plurality ofdielectric layers having a higher relative permittivity than that of theinsulating layers 21-25 that constitute the multi-layer substrate 2 arestacked in a direction perpendicular to the stacking direction of themulti-layer substrate 2. The plurality of counter electrodes 6 aredisposed within the ceramic body 5 so as to face against each other withthe dielectric layers interposed therebetween. Specifically, the counterelectrodes 6 are respectively arranged in parallel to the stackingdirection of the multi-layer substrate 2. The mounting electrodes 7A and7B are provided for an outer surface of the ceramic body 5 at positionsnear its both ends, and respectively connected to the plurality ofcounter electrodes 6 alternately. More specifically, the mountingelectrodes 7A and 7B are respectively disposed along surfaces facing thestacking direction of the multi-layer substrate 2, via the end surfacesbeing perpendicular to the surfaces in the stacking direction of theceramic body 5 and to the surfaces in the stacking direction of themulti-layer substrate 2.

Further, the wiring layer 32 of the resin sheet 12 is provided with aconnected conductor 32B. The connected conductor 32B is an electrodeconnecting the mounting electrode 7B of the chip capacitive element 4and the coil conductor 32A of the pattern coil 3.

Moreover, the wiring layer 34 of the resin sheet 14 is provided withconnected conductors 34A, 34B, and 34C. The connected conductor 34A isan electrode to which the mounting electrode 7A of the chip capacitiveelement 4 is connected by the via conductor 44 of the resin sheet 14.The connected conductor 34B is an electrode to which the mountingelectrode 7B of the chip capacitive element 4 is connected by the viaconductor 44 of the resin sheet 14. The connected conductor 34C is anelectrode to which the coil conductor 33A of the pattern coil 3 isconnected by the via conductor 44 of the resin sheet 14 and the viaconductor 43 of the resin sheet 13.

Furthermore, the wiring layer 35 of the resin sheet 15 is provided withmounting electrodes 35A, 35B, and 35C. The mounting electrode 35A is anelectrode connected to the connected conductor 34A of the resin sheet 14by the via conductor 45 of the resin sheet 15, and connected to anelectrode of the external substrate that is not depicted. Specifically,the mounting electrode 35A is connected to the mounting electrode 7A ofthe chip capacitive element 4 via the connected conductor 34A.

The mounting electrode 35B is an electrode connected to the connectedconductor 34B of the resin sheet 14 by the via conductor 45 of the resinsheet 15, and connected to an electrode of the external substrate thatis not depicted. Specifically, the mounting electrode 35B is connectedto the mounting electrode 7B of the chip capacitive element 4 via theconnected conductor 34B.

The mounting electrode 35C is an electrode connected to the connectedconductor 34C of the resin sheet 14 by the via conductor 45 of the resinsheet 15, and connected to an electrode of the external substrate thatis not depicted. Specifically, the mounting electrode 35C is connectedto the coil conductor 33A of the pattern coil 3 via the connectedconductor 34C.

FIG. 3 is an equivalent circuit schematic of the LC composite component1.

The pattern coil 3 and the chip capacitive element 4 are connected inseries. The pattern coil 3 is also connected between the mountingelectrode 35B and the mounting electrode 35C. The chip capacitiveelement 4 is connected between the mounting electrode 35B and themounting electrode 35A. The LC composite component 1 constitutes afilter circuit, and functions as a low-pass filter (LPF) by using themounting electrode 35A as a ground connecting electrode and the mountingelectrodes 35B and 35C as signal input/output terminals, for example.

FIGS. 4A, 4B, 4C, 4D, and 4E are side sectional views illustrating anexample of steps of manufacturing the LC composite component 1. In thefigures, a portion that constitutes a single LC composite component 1 isillustrated. The LC composite component 1 may be manufactured byproducing a plurality of LC composite components 1 at the same time byproviding a large number of LC composite components 1 over a large resinsheet, and then dicing the sheet into individual LC composite components1.

First, in a first step shown in FIG. 4A, the resin sheet 11 having aninsulating layer and the resin sheets 12-15 each having a metallic filmentirely over one side of an insulating layer are prepared. As themetallic film, a metallic foil such as a copper foil is used, forexample.

Next, in a second step shown in FIG. 4B, the metallic films of the resinsheets 12-15 are patterned by etching or the like to form the wiringlayers 32-35. Further, the openings 22A and 23A are defined respectivelyin the insulating layers of the resin sheets 12 and 13 by punching orthe like. In addition, the via conductors 42-45 are providedrespectively in the insulating layers of the resin sheets 12-15, eachvia conductor being provided by defining a penetrating hole thatpenetrates the insulating layer but not the metallic film by laser orthe like, and by providing a conductive material such as a conductivepaste within the penetrating hole.

Thereafter, in a third step shown in FIG. 4C, in a state in which thewiring layer 34 of the resin sheet 14 faces a side of the bottomsurface, the chip capacitive element 4 is disposed on a side of the topsurface of the resin sheet 14, the chip capacitive element 4 is bondedto the resin sheet 14 by thermocompression bonding. With this, themounting electrodes 7A and 7B of the chip capacitive element 4 arejoined to the via conductor 44 of the resin sheet 14.

Next, in a fourth step shown in FIG. 4D, the resin sheets 11-15 arestacked in a state in which the wiring layer 32 of the resin sheet 12faces a side of the top surface, the wiring layer 33 of the resin sheet13 faces the side of the top surface, the wiring layer 34 of the resinsheet 14 faces the side of the bottom surface, and the wiring layer 35of the resin sheet 15 faces the side of the bottom surface.

Then, in a fifth step shown in FIG. 4E, the resin sheets 11-15 arebonded by thermocompression bonding. With this, the resin sheets 11-15are joined with each other, and the LC composite component 1 ismanufactured.

As described above, the LC composite component 1 according to thisembodiment is configured such that the chip capacitive element 4 isdisposed within the pattern coil 3. Therefore, it is possible to reducea space for providing the chip capacitive element 4 in the LC compositecomponent 1. With this, the LC composite component 1 as a whole may bemade smaller as compared to a case in which the chip capacitive element4 is disposed outside the pattern coil 3. Further, by using athermoplastic resin for the multi-layer substrate 2, it is possible tomake a thermoplastic resin to flow at the same time as thermocompressionbonding, and it is possible to fill a cavity portion due to the openings22A and 23A within the multi-layer substrate 2, and to steadily fixintegrated components such as the chip capacitive element 4. Moreover,by covering a fragile ceramic body of the chip capacitive element 4 witha resin of the multi-layer substrate 2, it is possible to make theceramic body of the chip capacitive element 4 less susceptible tofracture on impact.

As the chip capacitive element 4 is disposed within the pattern coil 3,there is possibly a case in which a magnetic flux of the pattern coil 3is blocked by the chip capacitive element 4, and the inductance of thepattern coil 3 reduces.

However, in this embodiment, the chip capacitive element 4 includes theceramic body 5 made of a dielectric layer having a higher relativepermittivity than that of the multi-layer substrate 2, and therefore itis possible to make the chip capacitive element 4 smaller as compared toa case in which the chip capacitive element 4 includes a dielectriclayer having a relative permittivity that is substantially the same asthat of the multi-layer substrate 2. Accordingly, an amount of themagnetic flux blocked by the chip capacitive element 4 disposed withinthe pattern coil 3 decreases.

It should be noted that it is possible to provide a small capacitiveelement also in a case in which counter electrodes based on a pattern isprovided for the wiring layer of the multi-layer substrate 2, and themulti-layer substrate 2 as a whole is configured by a layer having ahigh relative permittivity. However, in this case, characteristics suchas an inductance may adversely deteriorate as the pattern coil 3 is alsoformed on the multi-layer substrate 2 having a high relativepermittivity. Therefore, as in this embodiment, it is possible todownsize the LC composite component 1 while achieving both a highinductance and a high capacitance by configuring a capacitive elementthat is desired to have a high relative permittivity by a dielectriclayer having a high relative permittivity and a pattern coil portion bya layer having a relative permittivity relatively lower than thedielectric layer.

Further, the chip capacitive element 4 is arranged such that thestacking direction of the ceramic body 5 is perpendicular to thestacking direction of the multi-layer substrate 2, that is, such thatthe counter electrodes 6 are respectively disposed in parallel with thestacking direction of the multi-layer substrate 2. As a result, adirection of magnetic flux within the pattern coil 3 substantiallymatches the stacking direction of the multi-layer substrate 2, and themagnetic flux of the pattern coil 3 passes through the ceramic body 5 ofthe chip capacitive element 4 while scarcely hitting against the counterelectrodes 6. Alternatively, the counter electrodes 6 may not berespectively disposed in parallel with the stacking direction of themulti-layer substrate 2. For example, the counter electrodes 6 may berespectively disposed in parallel with a planar surface of themulti-layer substrate 2.

Further, within the pattern coil 3, the via conductor 44 of the resinsheet 14 is provided so as to overlap the mounting electrodes 7A and 7Bof the chip capacitive element 4, when viewed along the stackingdirection of the multi-layer substrate 2. Therefore, as compared to acase in which the via conductor is displaced from the mountingelectrodes 7A and 7B of the chip capacitive element 4, an amount of themagnetic flux blocked by the via conductor 44 decreases.

Moreover, in the LC composite component 1 thus configured, its bottomsurface constitutes a mounting surface to an external substrate. Ingeneral, a region of the external substrate that faces the LC compositecomponent 1 is provided with a ground electrode and a mountingelectrode. Therefore, in a state in which the LC composite component 1is mounted on the external substrate, a magnetic field generated by thepattern coil 3 of the LC composite component 1 becomes weaker on a sideof the bottom surface than on a side of the top surface.

As illustrated in FIG. 4E, in the LC composite component 1, along thestacking direction of the multi-layer substrate 2, a center of thepattern coil 3 is near a center of the resin sheet 12 in a thicknessdirection, and a center of the chip capacitive element 4 is near aboundary between the resin sheet 12 and the resin sheet 13.Specifically, along the stacking direction of the multi-layer substrate2, the center of the chip capacitive element 4 is displaced to the sideof the bottom surface from the center of the pattern coil 3. Therefore,the chip capacitive element 4 is placed in a region where the magneticfield of the pattern coil 3 is weak. With this, a loop of the magneticfield may not be prevented in a region on the side of the top surfacewhere the magnetic field is strong.

As a result, it is possible to prevent an inductance of the pattern coil3 from decreasing. Therefore, it is easily possible to achieve a desiredinductance of the pattern coil 3, even if the chip capacitive element 4is disposed within the pattern coil 3 to make the LC composite component1 small.

Next, an LC composite component 51 according to a second embodiment ofthe present disclosure will be described.

FIG. 5 is a side sectional view illustrating the LC composite component51. FIG. 6 is an exploded plan view of the LC composite component 51 inwhich its layers are viewed in a planar view from their top surfaces.

The LC composite component 51 includes a multi-layer substrate 52,pattern coils 53A and 53B, and chip capacitive elements 54A and 54B. Thechip capacitive elements 54A and 54B here are chip capacitors. Thepattern coils 53A and 53B and the chip capacitive elements 54A and 54Bare disposed within the multi-layer substrate 52.

The multi-layer substrate 52 includes insulating layers 71, 72, 73, 74,75, 76, 77, 78, and 79. The multi-layer substrate 52 is configured suchthat the insulating layers 71-79 are stacked from a top surface to abottom surface in order.

The insulating layer 71 is made of a resin, has a rectangular outline ina planar view along the stacking direction, includes a wiring layer 81stacked over the top surface and a via conductor 91 penetrating from thetop surface to the bottom surface. The insulating layer 72 is made of aresin, has a rectangular outline in a planar view along the stackingdirection, includes a wiring layer 82 stacked over the top surface and avia conductor 92 penetrating from the top surface to the bottom surface.The insulating layer 73 is made of a resin, has a rectangular outline ina planar view along the stacking direction, includes a wiring layer 83stacked over the top surface and a via conductor 93 penetrating from thetop surface to the bottom surface. The insulating layer 74 is made of aresin, has a rectangular outline in a planar view along the stackingdirection, includes a wiring layer 84 stacked over the bottom surface aswell as a via conductor 94 and openings 74A and 74B penetrating from thetop surface to the bottom surface. The insulating layer 75 is made of aresin, has a rectangular outline in a planar view along the stackingdirection, includes a wiring layer 85 stacked over the bottom surface aswell as a via conductor 95 and openings 75A and 75B penetrating from thetop surface to the bottom surface. The insulating layer 76 is made of aresin, has a rectangular outline in a planar view along the stackingdirection, includes a wiring layer 86 stacked over the bottom surface aswell as a via conductor 96 and openings 76A and 76B penetrating from thetop surface to the bottom surface. The insulating layer 77 is made of aresin, has a rectangular outline in a planar view along the stackingdirection, includes a wiring layer 87 stacked over the bottom surface aswell as a via conductor 97 and openings 77A and 77B penetrating from thetop surface to the bottom surface. The insulating layer 78 is made of aresin, has a rectangular outline in a planar view along the stackingdirection, includes a wiring layer 88 stacked over the bottom surface aswell as a via conductor 98 penetrating from the top surface to thebottom surface. The insulating layer 79 is made of a resin, has arectangular outline in a planar view along the stacking direction,includes a wiring layer 89 stacked over the bottom surface as well as avia conductor 99 penetrating from the top surface to the bottom surface.

The pattern coil 53A includes coil conductors 81A, 82A, 83A, 84A, 85A,86A, 87A, and 88A, and has an inductance. The pattern coil 53B includescoil conductors 81B, 82B, 83B, 84B, 85B, 86B, 87B, and 88B, and has aninductance.

The coil conductors 81A and 81B are provided for the wiring layer 81,and applied to the top surface of the insulating layer 71. The coilconductors 82A and 82B are provided for the wiring layer 82, and appliedto the top surface of the insulating layer 72. The coil conductors 83Aand 83B are provided for the wiring layer 83, and applied to the topsurface of the insulating layer 73. The coil conductors 84A and 84B areprovided for the wiring layer 84, and applied to the bottom surface ofthe insulating layer 74. The coil conductors 85A and 85B are providedfor the wiring layer 85, and applied to the bottom surface of theinsulating layer 75. The coil conductors 86A and 86B are provided forthe wiring layer 86, and applied to the bottom surface of the insulatinglayer 76. The coil conductors 87A and 87B are provided for the wiringlayer 87, and applied to the bottom surface of the insulating layer 77.The coil conductors 88A and 88B are provided for the wiring layer 88,and applied to the bottom surface of the insulating layer 78.

The openings 74A, 75A, 76A, and 77A are disposed so as to overlap eachother when viewed along the stacking direction of the multi-layersubstrate 52. The coil conductors 81A, 82A, 83A, 84A, 85A, 86A, 87A, and88A extend so as to surround the openings 74A, 75A, 76A, and 77A whenviewed along the stacking direction of the multi-layer substrate 52.Further, the coil conductors 81A, 82A, 83A, 84A, 85A, 86A, 87A, and 88Aare connected by the via conductors 91, 92, 93, 94, 95, 96, 97, and 98so as to form a coiled shape of which the coil axis extends along thestacking direction of the multi-layer substrate 52.

Moreover, the openings 74B, 75B, 76B, and 77B are disposed so as tooverlap each other when viewed along the stacking direction of themulti-layer substrate 52. The coil conductors 81B, 82B, 83B, 84B, 85B,86B, 87B, and 88B extend so as to surround the openings 74B, 75B, 76B,and 77B when viewed along the stacking direction of the multi-layersubstrate 52. Further, the coil conductors 81B, 82B, 83B, 84B, 85B, 86B,87B, and 88B are connected by the via conductors 91, 92, 93, 94, 95, 96,97, and 98 so as to form a coiled shape of which the coil axis extendsalong the stacking direction of the multi-layer substrate 52.

The chip capacitive element 54A has a thickness substantially equal to atotal thickness of the insulating layers 74, 75, 76, and 77, and iscontained within a cavity defined by the openings 74A, 75A, 76A, and77A. As the openings 74A, 75A, 76A, and 77A are provided within the coilconductors 81A, 82A, 83A, 84A, 85A, 86A, 87A, and 88A, the chipcapacitive element 54A is disposed within the pattern coil 53A.

The chip capacitive element 54B has a thickness substantially equal to atotal thickness of the insulating layers 74, 75, 76, and 77, and iscontained within a cavity defined by the openings 74B, 75B, 76B, and77B. As the opening 74B, 75B, 76B, 77B are provided within the coilconductors 81B, 82B, 83B, 84B, 85B, 86B, 87B, and 88B, the chipcapacitive element 54B is disposed within the pattern coil 53B.

Further, as illustrated in FIG. 5, each of the chip capacitive elements54A and 54B includes a ceramic body 55, a plurality of counterelectrodes 56, and mounting electrodes 57A and 57B, and has acapacitance. The ceramic body 55 is configured such that dielectriclayers having a higher relative permittivity than that of the insulatinglayers that constitute the multi-layer substrate 52 are stacked in adirection perpendicular to the stacking direction of the multi-layersubstrate 52. The plurality of counter electrodes 56 are disposed withinthe ceramic body 55 so as to face against each other with the dielectriclayers interposed therebetween, and correspond to counter electrodesdefined in the scope of the disclosure. Specifically, the counterelectrodes 56 are arranged in parallel to the stacking direction of themulti-layer substrate 52. The mounting electrodes 57A and 57B areprovided for an outer surface of the ceramic body 55 at positions nearboth of its ends, and respectively connected to the plurality of counterelectrodes 56 alternately. More specifically, the mounting electrodes57A and 57B are respectively disposed along surfaces facing the stackingdirection of the multi-layer substrate 52, via the end surfaces beingperpendicular to the surfaces in the stacking direction of the ceramicbody 55 and to the surfaces in the stacking direction of the multi-layersubstrate 52.

Further, as illustrated in FIG. 6, the wiring layer 81 is provided withconnected conductors 81C and 81D. The wiring layer 82 is provided withconnected conductors 82C and 82D. The wiring layer 83 is provided withconnected conductors 83C and 83D. The wiring layer 88 is provided withconnected conductors 88C, 88D, 88E, and 88F. The wiring layer 89 isprovided with mounting electrodes 89A, 89B, 89C, 89D, and 89E.

The connected conductors 81C, 82C, and 83C are electrodes connecting themounting electrode 57A of the chip capacitive element 54A and the coilconductor 81A of the pattern coil 53A by the via conductors 91, 92, and93, as illustrated in FIG. 5. The connected conductors 81D, 82D, and 83Dare electrodes connecting the mounting electrode 57A of the chipcapacitive element 54B and the coil conductor 81B of the pattern coil53B by the via conductors 91, 92, and 93.

The connected conductor 88C is an electrode connected to the mountingelectrode 57A of the chip capacitive element 54A by the via conductor98. The connected conductor 88D is an electrode connected to themounting electrode 57A of the chip capacitive element 54B by the viaconductor 98. The connected conductor 88E is an electrode connected tothe mounting electrode 57B of the chip capacitive element 54A by the viaconductor 98. The connected conductor 88F is an electrode connected tothe mounting electrode 57B of the chip capacitive element 54B by the viaconductor 98.

The mounting electrode 89A is an electrode connected to the coilconductor 88A by the via conductor 99, and connected to an electrode ofthe external substrate that is not depicted. The mounting electrode 89Bis an electrode connected to the coil conductor 88B by the via conductor99, and connected to an electrode of the external substrate that is notdepicted. The mounting electrode 89C is an electrode connected to theconnected conductor 88C by the via conductor 99, and connected to anelectrode of the external substrate that is not depicted. Specifically,the mounting electrode 89C is connected to the mounting electrode 57A ofthe chip capacitive element 54A. The mounting electrode 89D is anelectrode connected to the connected conductor 88D by the via conductor99, and connected to an electrode of the external substrate that is notdepicted. Specifically, the mounting electrode 89D is connected to themounting electrode 57A of the chip capacitive element 54B via theconnected conductor 88D. The mounting electrode 89E is an electrodeconnected to the connected conductors 88E and 88F by the via conductor99, and connected to an electrode of the external substrate that is notdepicted. Specifically, the mounting electrode 89E is connected to themounting electrode 57B of the chip capacitive element 54A and themounting electrode 57B of the chip capacitive element 54B via theconnected conductor 88E, 88F.

FIG. 7 is an equivalent circuit schematic of the LC composite component51.

The pattern coil 53A, the chip capacitive element 54A, the chipcapacitive element 54B, and the pattern coil 53B are connected inseries. The pattern coil 53A is also connected between the mountingelectrode 89A and the mounting electrode 89C. The chip capacitiveelement 54A is connected between the mounting electrode 89C and themounting electrode 89E. The chip capacitive element 54B is connectedbetween the mounting electrode 89D and the mounting electrode 89E. Thepattern coil 53B is connected between the mounting electrode 89D and themounting electrode 89B. The LC composite component 51 constitutes afilter circuit, and functions as a dual system of low-pass filters(LPFs) by using the mounting electrode 89E as a ground connectingelectrode and the mounting electrodes 89A, 89B, 89C, and 89D as signalinput/output terminals, for example.

As described above, the LC composite component 51 according to thisembodiment is configured such that the chip capacitive element 54A isdisposed within the pattern coil 53A and the chip capacitive element 54Bis disposed within the pattern coil 53B. Therefore, it is possible toreduce a space for providing the chip capacitive elements 54A and 54B.With this, the LC composite component 51 as a whole may be made smalleras compared to a case in which the chip capacitive elements 54A and 54Bare respectively disposed outside the pattern coils 53A and 53B.

Further, in this embodiment, each of the chip capacitive elements 54Aand 54B is configured by the ceramic body 55 having a higher relativepermittivity than that of the multi-layer substrate 52, and therefore itis possible to make the chip capacitive elements 54A and 54B smaller ascompared to a case in which a dielectric layer having a relativepermittivity that is substantially the same as that of the multi-layersubstrate 52 is used. Accordingly, an amount of the magnetic fluxblocked by the chip capacitive elements 54A and 54B disposed within thepattern coils 53A and 53B decreases.

Moreover, the chip capacitive elements 54A and 54B are arranged suchthat the stacking direction of the ceramic body 55 is perpendicular tothe stacking direction of the multi-layer substrate 52, and the counterelectrodes 56 are respectively disposed in parallel with the stackingdirection of the multi-layer substrate 52. As a direction of magneticflux within the pattern coils 53A and 53B substantially matches thestacking direction of the multi-layer substrate 52, the magnetic flux ofthe pattern coils 53A and 53B passes through the ceramic bodies 55 ofthe chip capacitive elements 54A and 54B.

Furthermore, within the pattern coils 53A and 53B, the via conductors91, 92, 93, 98, and 99 are provided so as to overlap the mountingelectrodes 57A and 57B of the chip capacitive elements 54A and 54B, whenviewed along the stacking direction of the multi-layer substrate 52.Therefore, as compared to a case in which the via conductors 91, 92, 93,98, and 99 are displaced from the mounting electrodes 57A and 57B of thechip capacitive elements 54A and 54B, an amount of the magnetic fluxblocked by the via conductor 91, 92, 93, 98, 99 decreases.

Moreover, in the LC composite component 51 thus configured, its bottomsurface constitutes a mounting surface to an external substrate. Ingeneral, a region of the external substrate that faces the LC compositecomponent 51 is provided with a ground electrode and a mountingelectrode. Therefore, in a state in which the LC composite component 51is mounted on the external substrate, magnetic fields generated by thepattern coils 53A and 53B of the LC composite component 51 become weakeron a side of the bottom surface than on a side of the top surface.

As illustrated in FIG. 5, in the LC composite component 51, along thestacking direction of the multi-layer substrate 52, a center of the chipcapacitive elements 54A and 54B is displaced to the side of the bottomsurface from a center of the pattern coils 53A and 53B. Therefore, thechip capacitive elements 54A and 54B are placed in regions where themagnetic fields of the pattern coils 53A and 53B are weak. With this, aloop of the magnetic field may not be prevented in a region on the sideof the top surface where the magnetic field is strong.

As a result, it is possible to prevent inductances of the pattern coils53A and 53B from decreasing. Therefore, it is easily possible to achievedesired inductances of the pattern coils 53A and 53B, even if the chipcapacitive elements 54A and 54B are disposed within the pattern coils53A and 53B to make the LC composite component 51 small.

Next, an LC composite component according to a third embodiment of thepresent disclosure will be described.

FIG. 8A is a schematic view illustrating an LC composite component 101according to the third embodiment of the present disclosure. In FIG. 8A,the pattern coil is schematically illustrated as a wire coil.

The LC composite component 101 includes a multi-layer substrate 102,pattern coils 103A and 103B, and chip capacitive elements 104A and 104B.The chip capacitive elements 104A and 104B here are chip capacitors.

The pattern coil 103A and the pattern coil 103B are in a coiled shape ofwhich the coil axis extends along the stacking direction of themulti-layer substrate 102, and are adjacent to each other in a directionperpendicular to the stacking direction of the multi-layer substrate102. Further, magnetic flux within the pattern coil 103A and the patterncoil 103B is directed from a bottom surface toward a top surface of themulti-layer substrate 102.

In such a configuration, as the magnetic flux within the pattern coil103A and that within the pattern coil 103B adjacent to the pattern coil103A are directed in the same direction, distribution of magnetic fieldsare unevenly distributed within the pattern coils 103A and 103B, and themagnetic field becomes weaker as a distance to the adjacent pattern coilbecomes closer.

Therefore, in the LC composite component 101, in a direction in whichthe pattern coil 103A and the pattern coil 103B are arranged adjacently,a center of the chip capacitive element 104A is displaced to a side ofthe adjacent pattern coil 103B from a center of the pattern coil 103A.Further, a center of the chip capacitive element 104B is displaced to aside of the adjacent pattern coil 103A from a center of the pattern coil103B.

Therefore, an amount of the magnetic flux blocked by the chip capacitiveelements 104A and 104B decreases as compared to a case in which the chipcapacitive elements 104A and 104B are placed apart from each other, andit is possible to prevent reduction of inductances of the pattern coils103A and 103B.

FIG. 8B is a schematic view illustrating an LC composite component 151according to a modified example of the third embodiment. In FIG. 8B, thepattern coil is schematically illustrated as a wire coil.

The LC composite component 151 includes multi-layer substrate 152,pattern coils 153A and 153B, and chip capacitive elements 154A and 154B.The chip capacitive elements 154A and 154B here are chip capacitors.

The pattern coil 153A and the pattern coil 153B are in a coiled shape ofwhich the coil axis extends along the stacking direction of themulti-layer substrate 152, and are adjacent to each other in a directionperpendicular to the stacking direction of the multi-layer substrate152. Further, magnetic flux within the pattern coil 153A and magneticflux within the pattern coil 153B are directed to directions oppositefrom each other. Specifically, the magnetic flux within the pattern coil153A is directed from a bottom surface toward a top surface of themulti-layer substrate 152, and the magnetic flux within the pattern coil153B is directed from the top surface toward the bottom surface of themulti-layer substrate 152.

In such a configuration, as the magnetic flux within the pattern coil153A and that within the pattern coil 153B adjacent to the pattern coil103A are directed in the opposite directions, distribution of magneticfields are unevenly distributed within the pattern coils 153A and 153B,and the magnetic field becomes stronger as a distance to the adjacentpattern coils 153A and 153B becomes closer.

Therefore, in the LC composite component 151, in a direction in whichthe pattern coil 153A and the pattern coil 153B are arranged adjacently,a center of the chip capacitive element 154A is displaced to an oppositeside of the adjacent pattern coil 153B from a center of the pattern coil153A. Further, a center of the chip capacitive element 154B is displacedto an opposite side of the adjacent pattern coil 153A from a center ofthe pattern coil 153B.

Therefore, an amount of the magnetic flux blocked by the chip capacitiveelements 154A and 154B decreases as compared to a case in which the chipcapacitive elements 154A and 154B are placed close to each other, and itis possible to prevent reduction of inductances of the pattern coils153A and 153B.

Next, an LC composite component according to a fourth embodiment will bedescribed. The LC composite component described here has, in addition tothe filtering function, a function of ESD protection for letting largeelectric power such as static electricity to ground through an externalconnecting terminal.

FIG. 9A is a perspective view illustrating an LC composite component 201according to the fourth embodiment.

The LC composite component 201 includes a multi-layer substrate 2, apattern coil 3, and a chip capacitive element 204. The multi-layersubstrate 2 and the pattern coil 3 have the same configurations as thosein the first embodiment. The chip capacitive element 204 here is a chipvaristor, and has the same configuration as the chip capacitive element4 illustrated in FIG. 1B, but the ceramic body 5 is configured bysemiconductor ceramics. The semiconductor ceramics have a high relativepermittivity. The chip capacitive element 204 as a chip varistor has acharacteristic that a resistance rapidly decreases when a voltage over avaristor voltage is applied, and has a high capacitance similar to achip capacitor in a state in which a voltage under the varistor voltageis applied. The chip capacitive element 4 is disposed within the patterncoil 3.

FIG. 9B is an equivalent circuit schematic of the LC composite component201.

The LC composite component 201 includes mounting electrodes 35A, 35B,and 35C in the same configuration as those in the first embodiment. Thepattern coil 3 included in the LC composite component 201 is connectedin series between the mounting electrode 35B and the mounting electrode35C. Further, the chip capacitive element 204 is connected in seriesbetween the mounting electrode 35B and the mounting electrode 35A. Themounting electrode 35A is used as a ground connecting electrode. Themounting electrode 35B is connected to a control IC 212 and used as asignal input/output terminal. The mounting electrode 35C is connected toan the external device 211 such as an earphone jack, a loudspeaker, amicrophone, or a USB device via a connector that is not depicted, andused as a signal input/output terminal.

The LC composite component 201 functions as a low-pass filter (LPF) whena voltage lower than the varistor voltage is applied to the chipcapacitive element 204 as a chip varistor. Further, when a voltage equalto or higher than the varistor voltage is applied to the chip capacitiveelement 204, a resistance between the mounting electrode 35B and themounting electrode 35A becomes low to let current flow to the ground.Thus the LC composite component 201 functions as an electrostaticdischarge protection circuit. Therefore, by providing the LC compositecomponent 201 for a connecting line between the external device 211 andthe control IC 212, it is possible to remove noises in signalstransmitted between the external device 211 and the control IC 212, andto provide electrostatic discharge protection between the externaldevice 211 and the control IC 212.

In the LC composite component 201 according to this embodiment, the chipcapacitive element 204 is also provided within the pattern coil 3.Therefore, it is possible to reduce a space for providing the chipcapacitive element 204 in the LC composite component 201. With this, theLC composite component 201 as a whole may be made smaller as compared toa case in which the chip capacitive element 204 is disposed outside thepattern coil 3.

Further, it is possible to downsize the chip capacitive element 204 byconfiguring the chip capacitive element 204 having a higher relativepermittivity than that of the multi-layer substrate 2. Therefore, anamount of the magnetic flux blocked by the chip capacitive element 204within the pattern coil 3 is small, and it is possible to downsize theLC composite component 201 while achieving both a high inductance and ahigh capacitance.

Moreover, the chip capacitive element 204 is disposed such that thecounter electrodes are in parallel with the stacking direction of themulti-layer substrate 2 so that the magnetic flux of the pattern coil 3passes through the chip capacitive element 204 without hitting againstthe counter electrodes. With this, it is also possible for the LCcomposite component 201 to achieve a high inductance.

As a result, it is possible to prevent an inductance of the pattern coil3 from decreasing. Therefore, it is easily possible to achieve a desiredinductance of the pattern coil 3, even if the chip capacitive element204 is disposed within the pattern coil 3 to make the LC compositecomponent 201 small.

Next, an LC composite component according to a fifth embodiment will bedescribed. The LC composite component described here is providedmonolithically with a substrate on which a control IC is mounted.

FIG. 10A is a perspective view illustrating an LC composite component250 according to the fifth embodiment.

The LC composite component 250 includes a multi-layer substrate 252, acontrol IC 212, and an earphone jack 253 as an external device. Thecontrol IC 212 is a surface-mount component, and surface-mounted on oneprincipal surface of the multi-layer substrate 252. The earphone jack253 is a surface-mount component to which an earphone is connected, andsurface-mounted on one principal surface of the multi-layer substrate252. The earphone jack 253 is provided with an insertion hole throughwhich a terminal of an earphone is inserted.

The multi-layer substrate 252 is configured by a total of fiveinsulating layers stacked one above the other, and includes the controlIC 212 and the earphone jack 253 surface-mounted thereon as well as anLC unit 251 built therein. The LC unit 251 includes a pattern coil 3 anda chip capacitive element 204 as a chip varistor. The LC unit 251 may beconfigured by a chip capacitor, in place of the chip varistor. Thecontrol IC 212, the earphone jack 253, and the LC unit 251 are connectedto each other via internal wiring (not depicted) provided within themulti-layer substrate 252.

FIG. 10B is a circuit diagram of the LC composite component 250. Thepattern coil 3 is connected in series between the earphone jack 253 andthe control IC 212. The chip capacitive element 204 is connected inseries between the control IC 212 and the ground.

In the LC composite component 250, the chip capacitive element 204 andthe pattern coil 3 function as a low-pass filter (LPF) when a voltagelower than a varistor voltage is applied to the chip capacitive element204 being a chip varistor. Further, when a voltage equal to or higherthan the varistor voltage is applied to the chip capacitive element 204,a resistance of the chip capacitive element 204 becomes low to letcurrent flow to the ground. Therefore, it is possible for the LCcomposite component 250 to remove noises in transmitted signals in aconnecting line between the earphone jack 253 being an external deviceand the control IC 212, and to provide electrostatic dischargeprotection.

Moreover, in the LC composite component 250, the chip capacitive element204 is also provided within the pattern coil 3. With this, the LCcomposite component 250 as a whole may be made smaller as compared to acase in which the chip capacitive element 204 is disposed outside thepattern coil 3.

Furthermore, the chip capacitive element 204 has a higher relativepermittivity than that of the multi-layer substrate 252. Therefore, anamount of the magnetic flux blocked by the chip capacitive element 204within the pattern coil 3 is small, and it is possible to downsize theLC composite component 250 while achieving both a high inductance and ahigh capacitance.

Further, the chip capacitive element 204 is disposed such that thecounter electrodes are in parallel with the stacking direction of themulti-layer substrate 252 so that the magnetic flux of the pattern coil3 passes through the chip capacitive element 204 while scarcely hittingagainst the counter electrodes. With this, it is also possible for theLC composite component 250 to achieve a high inductance.

As a result, it is possible to prevent an inductance of the pattern coil3 from decreasing. Therefore, it is easily possible to achieve a desiredinductance of the pattern coil 3, even if the chip capacitive element204 is disposed within the pattern coil 3 to make the LC compositecomponent 250 small.

Next, an LC composite component according to a sixth embodiment will bedescribed. In the following, like components as in the LC compositecomponent according to the first embodiment are denoted by likereference numerals.

FIG. 11A is an equivalent circuit schematic of an LC composite component301 according to the sixth embodiment. The LC composite component 301includes, in addition to the pattern coil 3 and the chip capacitiveelement 4, a first inductor 305A and a second inductor 305B. The firstinductor 305A and the second inductor 305B are connected in parallelwith each other, and connected between the chip capacitive element 4 andthe mounting electrode 35A. In the LC composite component 301, by usingthe mounting electrode 35A as a ground connecting electrode, themounting electrode 35C as a first signal input/output terminal, and themounting electrode 35B as a second signal input/output terminal, anattenuation pole based on series resonance between the first inductor305A and the second inductor 305B and the chip capacitive element 4 isset in filter characteristics of a filter circuit configured by thepattern coil 3 and the chip capacitive element 4.

FIG. 11B is an exploded perspective view of the LC composite component301.

The LC composite component 301 includes a multi-layer substrate 302. Themulti-layer substrate 302 is configured such that the resin sheets 11,12, 13, 14, and 15 are stacked from a top surface to a bottom surface.The pattern coil 3 is disposed over the resin sheets 12 and 13. Thefirst inductor 305A and the second inductor 305B are respectivelyconfigured by the connected conductors 306A and 306B provided for theresin sheet 14.

FIG. 12 is an exploded plan view of the multi-layer substrate 302 inwhich its layers are viewed in a planar view from their top surfaces.

The resin sheet 11 includes an insulating layer 21 in a flat plateshape. The resin sheet 12 includes an insulating layer 22 having theopening 22A, a coil conductor 332, and via conductors 342A and 342B. Theresin sheet 13 includes an insulating layer 23 having the opening 23A, acoil conductor 333, and via conductors 343A and 343B. The resin sheet 14includes an insulating layer 24 in a flat plate shape, connectedconductors 306A, 306B, 306C, and 306D, pad conductors 307A, 307B, 307C,307D, 307E, and 307F, and via conductors 344A, 344B, 344C, and 344D. Theresin sheet 15 includes an insulating layer 25 in a flat plate shape,mounting electrodes 35A, 35B, 35C, and 35D, and a via conductor 345.

The coil conductor 332 and the coil conductor 333 are connected by thevia conductor 342A to constitute the pattern coil 3. One end of thepattern coil 3 is connected to the connected conductor 306D of the resinsheet 14 by the via conductor 342B, the via conductor 343B, and the viaconductor 344B. The other end of the pattern coil 3 is connected to thepad conductor 307C of the resin sheet 14 by the via conductor 343A andthe via conductor 344A. The pad conductor 307C is connected to themounting electrode 35C by the via conductor 345 of the resin sheet 15.

The chip capacitive element 4 is disposed within the openings 22A and23A of the resin sheets 12 and 13, and connected to the pad conductors307E and 307F by the via conductors 344C and 344D of the resin sheet 14.The pad conductor 307E is connected to the pad conductors 307D and 307Avia the connected conductors 306A and 306B. The pad conductors 307D and307A are respectively connected to the mounting electrodes 35D and 35Aby the via conductor 345 of the resin sheet 15.

The pad conductor 307F is connected to the pad conductor 307B via theconnected conductor 306C. The pad conductor 307B is connected to themounting electrode 35B by the via conductor 345 of the resin sheet 15.Further, the pad conductor 307F is connected to the via conductor 344Bvia the connected conductor 306D, and to the pattern coil 3 by the viaconductors 342B, 343B, and 344B.

In the LC composite component 301 according to this embodiment, it ispossible to downsize the LC composite component 301 while achieving botha high inductance of the pattern coil 3 and a high capacitance of thechip capacitive element 4 by configuring the chip capacitive element 4so as to have a relative permittivity higher than that of themulti-layer substrate 302, and such that the magnetic flux of thepattern coil 3 passes while scarcely hitting against the counterelectrodes of the chip capacitive element 4.

Further, according to the LC composite component 301 of this embodiment,it is possible to adjust an attenuation pole by providing theattenuation pole for the filter characteristics using the first inductor305A and the second inductor 305B respectively configured by theconnected conductors 306A and 306B of the resin sheet 14, and byadjusting a coupling state between the first inductor 305A and thesecond inductor 305B and the pattern coil 3.

Specifically, the connected conductor 306A is wired such that theconnected conductor 306A of the resin sheet 14 faces a part of the coilconductor 333 of the resin sheet 13, and such that a current flowstherethrough in the same direction as that in the coil conductor 333.With this, magnetic field coupling of the first inductor 305A in phasewith the pattern coil 3 (by a positive coupling factor) is achieved.Further, the connected conductor 306B is wired such that the connectedconductor 306B of the resin sheet 14 faces a part of the coil conductor333 of the resin sheet 13, and such that a current flows therethrough ina direction opposite from that in the coil conductor 333. With this,magnetic field coupling of the second inductor 305B in reversed phasewith the pattern coil 3 (by a negative coupling factor) is achieved.

In this manner, by achieving magnetic field coupling between the firstand the second inductance configured by the connected conductors 306Aand 306B and the pattern coil 3, respectively, it is possible toaccurately adjust filter characteristics or the like of the LC compositecomponent 301 by controlling the coupling state.

Here, in the LC composite component 301 according to this embodiment,various examples of wiring of the connected conductor and relationbetween the filter characteristics will be described.

FIG. 13A is a plan view illustrating the resin sheet 14A according to amodified example of the LC composite component of this embodiment. FIG.13B is a plan view illustrating the resin sheet 14B according to amodified example of the LC composite component of this embodiment. FIG.13C is a plan view illustrating the resin sheet 14C according to amodified example of the LC composite component of this embodiment.

In the resin sheet 14A illustrated in FIG. 13A, out of the connectedconductors 306A and 306B, the connected conductor 306A is omitted, andonly the second inductor 305B that achieves magnetic field coupling inreversed phase with the pattern coil 3 is provided.

In the resin sheet 14B illustrated in FIG. 13B, out of the connectedconductors 306A and 306B, the connected conductor 306B is omitted, andonly the first inductor 305A that achieves magnetic field coupling inphase with the pattern coil 3 is provided.

In the resin sheet 14C illustrated in FIG. 13C, both of the connectedconductors 306A and 306B are provided without being omitted, but theconnected conductor 306A is wired such that a current flows in thedirection opposite from that in the coil conductor 333. With this,magnetic field coupling between the first inductor 305A and the patterncoil 3 in reversed phase (buy a negative coupling factor) is achieved.

FIG. 14 is a diagram exemplary illustrating filter characteristics ofthe modified examples respectively using the resin sheet 14A to theresin sheet 14C. The chart shows an insertion loss in a frequency nearthe attenuation pole due to the inductor and the chip capacitiveelement. As illustrated in FIG. 14, by appropriately adjusting(modifying) the coupling state between the first inductor 305A and thesecond inductor 305B with the pattern coil 3, it is possible to adjustfilter characteristics of the LC composite component, to increase inparticular the attenuation pole. Therefore, by appropriately setting thewiring of the first inductor 305A or the second inductor 305B, it iseasily possible to achieve desired filter characteristics.

While the example in which a chip capacitor is used as the chipcapacitive element in this embodiment, the chip capacitive element maybe a chip varistor or the like. Further, the LC composite component maybe configured as a composite substrate on which the multi-layersubstrate along with other circuit elements is mounted. In addition, inthe second embodiment to the sixth embodiment, the first inductor or thesecond inductor that achieves magnetic field coupling with the patterncoil may be provided, similarly to this embodiment.

REFERENCE SIGNS LIST

-   1, 51, 101, 151, 201, 250, 301 LC composite component-   2, 52, 102, 152, 252, 302 multi-layer substrate-   3, 53A, 53B, 103A, 103B, 153A, 153B pattern coil-   4, 54A, 54B, 104A, 104B, 154A, 154B, 204 chip capacitive element-   5, 55 ceramic body-   6, 56 capacitor electrode-   7A, 7B, 57A, 57B mounting electrode-   11, 12, 13, 14, 15 resin sheet-   21, 22, 23, 24, 25, 71, 72, 73, 74, 75, 76, 77, 78, 79 insulating    layer-   22A, 23A, 74A, 75A, 76A, 77A, 74B, 75B, 76B, 77B opening-   32, 33, 34, 35, 81, 82, 83, 84, 85, 86, 87, 88, 89 wiring layer-   32A, 33A, 81A, 82A, 83A, 84A, 85A, 86A, 87A, 88A, 81B, 82B, 83B,    84B, 85B, 86B, 87B, 88B coil conductor-   32B, 34A, 34B, 34C, 81C, 82C, 83C, 81D, 82D, 83D, 88C, 88D, 88E,    88F, 89A, 89B, 89C, 89D, 89E, 306A, 306B, 306C, 306D connected    conductor-   35A, 35B, 35C, 35D mounting electrode-   42, 43, 44, 45, 91, 92, 93, 94, 95, 96, 97, 98, 99 via conductor-   211 external device-   212 control IC-   251 LC unit-   253 earphone jack

What is claimed is:
 1. An LC composite component comprising: amulti-layer substrate configured such that a plurality of insulatinglayers are stacked; a first pattern coil forming a coiled shape of whicha first coil axis extends along a stacking direction of the multi-layersubstrate, and including a coil conductor disposed between the pluralityof insulating layers; a chip capacitive element including a body made ofa material different from that of the plurality of insulating layers; asecond pattern coil, being adjacent to the first pattern coil on a sideperpendicular to the stacking direction of the multi-layer substrate,and forming a coiled shape of which a second coil axis extends along thestacking direction of the multi-layer substrate, wherein a direction ofmagnetic flux within the first pattern coil is the same as a directionof magnetic flux within the second pattern coil, and a center of thechip capacitive element, in a direction along which the first patterncoil and the second pattern coil are adjacent, is displaced toward aside of the second pattern coil from a center of the first pattern coil,all of the chip capacitive element is disposed within the coil conductorof the first pattern coil, and the direction of magnetic flux within thefirst pattern coil substantially matches the stacking direction of themulti-layer substrate.
 2. The LC composite component according to claim1, wherein the chip capacitive element further includes counterelectrodes that face against each other with the body and is disposedsuch that each of the counter electrodes is in parallel with thestacking direction of the multi-layer substrate.
 3. The LC compositecomponent according to claim 1, wherein the chip capacitive elementincludes one principal surface facing the stacking direction of themulti-layer substrate, the one principal surface is a mounting surfacefacing an external substrate, and the center of the chip capacitiveelement in the stacking direction of the multi-layer substrate isdisplaced toward a side of the mounting surface from the center of thefirst pattern coil in the stacking direction of the multi-layersubstrate.
 4. The LC composite component according to claim 1, whereinthe chip capacitive element includes a mounting electrode facing thestacking direction of the multi-layer substrate, the multi-layersubstrate includes via conductors on a top and a bottom of themulti-layer substrate in the stacking direction of the multi-layersubstrate with respect to the chip capacitive element, the viaconductors extending from the mounting electrode along the stackingdirection of the multi-layer substrate as a part of wiring connected tothe chip capacitive element, and the mounting electrode is connectedbetween the via conductors.
 5. The LC composite component according toclaim 1, wherein the chip capacitive element has counter electrodes thatface against each other with the body and is disposed such that each ofthe counter electrodes is in parallel with a planar surface of themulti-layer substrate.
 6. An LC composite component comprising: amulti-layer substrate configured such that a plurality of insulatinglayers are stacked; a first pattern coil forming a coiled shape of whicha first coil axis extends along a stacking direction of the multi-layersubstrate, and including a coil conductor disposed between the pluralityof insulating layers; a chip capacitive element including a body made ofa material different from that of the plurality of insulating layers;and a second pattern coil being adjacent to the first pattern coil on aside perpendicular to the stacking direction of the multi-layersubstrate, and forming a coiled shape of which a second coil axisextends along the stacking direction of the multi-layer substrate,wherein a direction of magnetic flux within the first pattern coil isopposite from a direction of magnetic flux within the second patterncoil, a center of the chip capacitive element, in a direction alongwhich the first pattern coil and the second pattern coil are adjacent,is displaced toward a side opposite from the second pattern coil from acenter of the first pattern coil, all of the chip capacitive element isdisposed within the coil conductor of the first pattern coil, and thedirection of magnetic flux within the first pattern coil substantiallymatches the stacking direction of the multi-layer substrate.
 7. The LCcomposite component according to claim 1, wherein a filter circuit isconfigured by connecting the first pattern coil and the chip capacitiveelement.
 8. The LC composite component according to claim 1, wherein thechip capacitive element is a chip capacitor.
 9. The LC compositecomponent according to claim 1, wherein the chip capacitive element is achip varistor.
 10. An LC composite component comprising: a multi-layersubstrate configured such that a plurality of insulating layers arestacked; a first pattern coil forming a coiled shape of which a firstcoil axis extends along a stacking direction of the multi-layersubstrate, and including a coil conductor disposed between the pluralityof insulating layers; a chip capacitive element including a body made ofa material different from that of the plurality of insulating layers;and a first inductor configured by a first conductor extending andfacing the first pattern coil between the plurality of insulatinglayers, and connected to the first pattern coil via the chip capacitiveelement, wherein all of the chip capacitive element is disposed withinthe coil conductor of the first pattern coil, and wherein a direction ofmagnetic flux within the first pattern coil substantially matches thestacking direction of the multi-layer substrate.
 11. The LC compositecomponent according to claim 10, further comprising: a first signalinput/output terminal; a second signal input/output terminal; and aground connecting electrode, wherein the first pattern coil is connectedbetween the first signal input/output terminal and the second signalinput/output terminal, the chip capacitive element has a first endconnected to a connecting point between the first pattern coil and thesecond signal input/output terminal, and the first inductor is connectedbetween a second end of the chip capacitive element and the groundconnecting electrode.
 12. The LC composite component according to claim10, wherein in a region in which the first inductor faces the firstpattern coil, a direction of a current flowing through the firstinductor is the same as a direction of a current flowing through thefirst pattern coil.
 13. The LC composite component according to claim10, wherein in a region in which the first inductor faces the firstpattern coil, a direction of a current flowing through the firstinductor is opposite from a direction of a current flowing through thefirst pattern coil.
 14. The LC composite component according to claim 10further comprising: a second inductor configured by a second conductorextending and facing the first pattern coil between the plurality ofinsulating layers, and connected to the first inductor in parallel. 15.The LC composite component according to claim 14, wherein in a region inwhich the second inductor faces the first pattern coil, a direction of acurrent flowing through the second inductor is the same as a directionof a current flowing through the first pattern coil.
 16. The LCcomposite component according to claim 14, wherein in a region in whichthe second inductor faces the first pattern coil, a direction of acurrent flowing through the second inductor is opposite from a directionof a current flowing through the first pattern coil.